Comment by rayval

Here's my version in C:

    int main(int argc, char ** argv) 
    { 
    	long *n1,*n2;
    	int row,i;

    	row=0; N1[0]=1L; print_row(row,N1);

    	while(row++ < MAX_ROWS)
    	{
    		for(i=0, n1 = N1, n2=N2; i<MAX_BUF && *n1; i++)
    		{
    			if (i==0 )        n2[i] = 0       + n1[i];
    			else if(n1[i]==0) n2[i] = n1[i-1] + 0;
    			else              n2[i] = n1[i-1] + n1[i];
    		}
    		print_row(row,N2);
    		for(n1=N1,n2=N2; *n2; ) *n1++ = *n2++;
    	}
    }

    void print_row(int row,long*n)
    {
        printf("row #%d",row);
        while(*n) { printf(" %ld ", *n++);}
        printf("\n");
    }

This works through the size of long int (at least 50 rows).